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Safe return to port: a seamless approach

With cruise ships costing up to £1bn, it may surprise some that the defects period for a new vessel is only 12 months. Dr. Luis Guarin, partner and naval architect at Brookes Bell, explains why the safety principles embedded during design and construction must not be compromised

he focus on safety does not remain constant, but passes like a baton in a race. Beginning with the concept design and the naval architect, it passes to the shipyard and on to the ship operator and crew. With substantial visitor traffic and near constant use, vessels will return to the yard every five years or so for major refurbishment and modernisation, with consequent safety implications to the ship’s services and functions. It is essential that access to and understanding of safety requirements should be visible and accessible at every stage of a vessel’s lifetime, from the drawing board to the dockside.

One important aspect of vessel safety is encompassed in the SOLAS ‘Safe Return to Port’ (SRTP) requirements, which present significant challenges for shipowners, operators and, particularly, crew. SRTP requires crew to contain emergency fires or flooding incidents defined in the SRTP regulations and recover the operability of affected essential systems and the ship.

Dr Luis Guarin, partner and naval architect at Brookes Bell

Challenge lies in implementation

Under the SRTP regulations, which apply to all new medium and large passenger vessels and highly occupied Special Purpose Ships, performance requirements for ‘essential systems’ must be demonstrated to remain operational following fire and flooding damages that do not exceed a certain pre-defined ‘casualty threshold’.

“The biggest challenge with the SRTP regulations lies in implementation by the ship’s crew”

After the SRTP regulations came into force on 1 July 2010, shipbuilders typically achieved compliance by carrying out Failure Mode Effect Analysis (FMEA) for each essential system, culminating in an extensive FMEA report for each system approved by a class society on behalf of a vessel’s flag state. The method was applied separately and independently of the rest of the design process and thus easily adding complexity and costs.

The biggest challenge with the SRTP regulations lies in implementation by the ship’s crew, who must interpret the outcome of the FMEA studies for each essential system and use the information to develop crew procedures that ensure compliance in an emergency.

Actions required to recover operability of systems

While the SRTP requirements are simple in essence, they have huge implications during ship operation. These include the number of required manual steps to recover the operability of the essential ship systems for a single fire or flood scenario, which may range from a few to hundreds of individual actions. Some of these include actions related to containing flooding; closing valves in different locations; recovering the operability of ballast systems and fuel transfer systems; maintaining propulsion; maintaining communication and navigation; moving passengers to safe, heated and ventilated areas; and maintaining the provision of basic amenities such as food, drinking water and toilets.

“Upon delivery of a new vessel, there is a need to validate the design assumptions made in the FMEA studies”

Shipowners and operators must also be mindful that the hundreds of individual actions needed to recover the operability of essential ship systems could require application in a huge number of scenarios. For example, in Brookes Bell’s experience, the average number of different manual actions required to recover the operability of the essential ship systems on a vessel could be up to 50 for a single scenario, which need to be applied to up to 200 different scenarios. This means 10,000 different points are necessary to ensure compliance in emergency situations.

Achieving this requires storage and efficient access to vast amounts of information and means the traditional paper copies of muster lists and crew action cards may not be a viable solution. Furthermore, upon delivery of a new vessel, there is a need to validate the design assumptions made in the FMEA studies in order to ensure any discrepancies between compliance during vessel design and operation can be addressed. For example, most FMEA studies are carried out at early design stages and the routing of most systems connections (i.e. cables and pipes) are only consolidated towards the end of the basic design process and changes may take place even down to the installation phases. This creates a necessity to check that all design information can be effectively applied to ensure SRTP compliance during vessel operation.

Suite view of the sea - Royal Caribbean is actually the biggest – yet one of the most understated – luxury accommodation providers in the cruise market.Credit: Royal Caribbean, SBW-Photo

Safe return to port: a lifelong process

SRTP cannot be considered finalised at the vessel delivery; it is a lifelong process, which needs to be well planned and organised throughout the lifecycle. It needs to live throughout all the upgrades and possible conversions and support the crew during maintenance work as well.

Once crew procedures to recover the operability of essential ship systems are defined, continuous and systematic drills need to be conducted to ensure that the crew members tasked with carrying out manual actions are familiar and competent with the emergency control procedures in line with the correct design intentions and for all SRTP scenarios. This presents additional challenges including:

Planning of and conducting SRTP drills is likely to require extensive efforts due to the large number of scenarios and associated manual actions;

Manual actions may involve sequential steps carried out at different locations throughout the ship, requiring, for example, specific access arrangements;

This logistical information (not necessarily provided in the FMEA studies) needs to be defined and recorded in a systematic manner and made available to crew throughout the life of the ship, including all possible maintenance work and modifications.

“In an emergency fire or flood situation, it will be necessary to increase crew workload "

In an emergency fire or flood situation, it will be necessary to increase crew workload to ensure damage control efforts, muster list activities and SRTP requirements are all adhered to with a specified one hour time period. These additional tasks will put pressure on the operational command and crew themselves to plan and carry out the plan as efficiently as possible.

SRTP compliance is also made more challenging by high crew turnover that is inherent within the passenger and cruise industry. Steps need to be taken to ensure acquired SRTP knowledge is not lost upon the departure of an individual or individuals, and that the process of increasing competence for new crew members becomes faster, more efficient and controlled.

Software ensures timely return to operation

Brookes Bell has provided FMEA software for SRTP design and verification since 2010, working in partnership with shipowners and operators to support crew in achieving SRTP compliance for vessels in operation. Brookes Bell Safety at Sea has developed a SRTP on-board crew advisory system, designed to be an emergency information management system, with the capability to:

“During refurbishment it is vital to minimise yard time and return the vessel to income generation in the shortest timescale"

Cruise owners know that during refurbishment it is vital to minimise yard time and return the vessel to income generation in the shortest timescale. Investing in system modelling at vessel design stage will provide shipowners with essential data that will ensure any works maintain the same level of system redundancy without the need to repeat the whole build checks. This seamless approach to safety will deliver long-term efficiency over the lifetime of a vessel while maintaining SRTP requirements, whenever and wherever the renovation is required.